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Air France blows a jug over North Atlantic

Posted: Sat Sep 30, 2017 11:36 pm
by ScudRunner-d95

Re: Air France blows a jug over North Atlantic

Posted: Sun Oct 01, 2017 1:00 am
by vanNostrum
No fan blades left? :o
I wonder how much drag that engine created
No knowing any better I would have guessed that an engine
was more likely to disintegrate at a very high power setting rather than cruise
 

Re: Air France blows a jug over North Atlantic

Posted: Mon Oct 02, 2017 12:01 pm
by Liquid Charlie
I'll bet the pilots are pissed. Cosmetics made them land in bum fuck no where. I'm sure if they had their choice it would have been a more major centre with better support to handle that many pax.

Re: Air France blows a jug over North Atlantic

Posted: Wed Oct 04, 2017 4:28 pm
by Eric Janson
[quote author=vanNostrum link=topic=7191.msg19524#msg19524 date=1506819645]
No fan blades left? :o
I wonder how much drag that engine created
No knowing any better I would have guessed that an engine
was more likely to disintegrate at a very high power setting rather than cruise
[/quote]

Engines are already running at a high power setting in cruise.

Example:- On my aircraft cruise power is around 88% N1 (the fan speed is 88% of rated maximum).

In this case it looks like something sheared or seized. I'm sure this is being looked at very closely.

Re: Air France blows a jug over North Atlantic

Posted: Thu Oct 05, 2017 2:11 am
by vanNostrum
[quote author=Eric Janson link=topic=7191.msg19605#msg19605 date=1507134516]
[quote author=vanNostrum link=topic=7191.msg19524#msg19524 date=1506819645]
No fan blades left? :o
I wonder how much drag that engine created
No knowing any better I would have guessed that an engine
was more likely to disintegrate at a very high power setting rather than cruise
[/quote]

Engines are already running at a high power setting in cruise.

Example:- On my aircraft cruise power is around 88% N1 (the fan speed is 88% of rated maximum).

In this case it looks like something sheared or seized. I'm sure this is being looked at very closely.
[/quote]


Eric
I have zero experience operating a turbine engine so I'm happy to learn :)
My comment on the likelihood of an engine disintegrating at a higher power setting
is based on I making some assumptions  :-\


T O and climb requires higher power settings than cruise
[size=small][font=Verdana]Higher P S produces higher stress and temperatures in the engine, therefore increase[/font][/size]
[size=2]risk of structural failure[/size]
[size=2] A turbofan at 85% N1 at lower altitudes, where T O and climb takes place, produces higher temperatures and stress in  the engine than [/size]
[size=2]the same RPM at cruise[/size]
[size=2]Centripetal force in the rotating parts varies with the square of the rotating velocity[angular][/size]
[size=2]Increasing N1 from 85% to 96% increases CF by more than 20% and the stress on the rotating parts[/size]
Are there  there are any stats regarding in  what face of flight are turbofan engines structural failures more
likely to occur ? 
Be interesting to know




Re: Air France blows a jug over North Atlantic

Posted: Thu Oct 05, 2017 5:31 am
by Eric Janson
@vanNostrum

Everything you're stating is correct.

I don't have statistics but I'm sure they'll show the highest failure rate on take-off and initial climb.